The vehicular power conversion device mounted on railroad vehicles uses the power conversion semiconductor elements to convert the power supplied from the overhead line and outputs the converted power to the vehicle drive motor. The semiconductor elements generate heat during the power conversion. In order to prevent overheating of the semiconductor elements, the vehicular power conversion device generally has a cooler. Coolers utilizing the vehicle-induced turbulence for cooling the semiconductor elements have been proposed in the prior art (for example, see Patent Literature 1).
The cooler (cooling structure) of the vehicular power conversion device of the Patent Literature 1 has a radiator disposed between the vehicle floor board and vehicle bottom panel for cooling the vehicular power conversion device and air vents formed in the vehicle bottom panel in front of and behind the radiator. Heat-radiating fins are formed in the radiator and heat exchange occurs between the heat-radiating fins and the air as the air passes over the radiator.